Field
Exemplary embodiments relate to a degradation compensation apparatus, a display device including the degradation compensation apparatus, and a degradation compensation method.
Discussion of the Background
The importance of display devices has steadily grown with recent developments in multimedia technology. As a result, a variety of display devices, such as a liquid crystal display (LCD) device, an organic electroluminescent (EL) display device, and the like, have been developed and widespread.
The organic EL display device, which is a display device emitting light by electrically exciting a phosphorous organic compound, displays an image by voltage- or current-programming a plurality of organic light-emitting diodes (OLEDs) that are arranged in a matrix form. A driving method of the organic EL display device may be classified into a passive matrix-type driving method and an active matrix-type driving method using thin-film transistors (TFTs). According to the passive matrix-type driving method, anodes and cathodes are arranged to be orthogonal to each other so that a desired line to be driven is selected. According to the active matrix type driving method, TFTs are coupled to respective indium tin oxide (ITO) pixel electrodes so that the organic EL display device is driven by a voltage maintained by the capacitance of a capacitor coupled to the gate of each of TFTs.
However, the efficiency of the organic EL display device may vary over time as a result of the degradation of the OLEDs, and thus, the organic EL display device may not be able to display an image with a desired luminance. More specifically, the OLEDs may gradually degrade over time, and may thus emit light with a lower luminance in response to the same data signal.
To compensate for a luminance decrease caused by the degradation of the OLEDs, an additional unit may be required. Also, for a proper operation of the additional unit, gray data regarding each area in an image input to the organic EL display device may need to be stored.
However, since not all images input to the organic EL display device can be stored, the storage of gray data regarding each input image is a critical issue.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concept, and, therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.